Do glFinish before sending snapshot latency info to browser

ui/gl/gl_surface.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "ui/gl/gl_surface.h"
 
 #include <vector>
 
 #include "base/command_line.h"
 #include "base/lazy_instance.h"
@@ skipping 172 matching lines @@
 }
 
 bool GLSurface::SetDrawRectangle(const gfx::Rect& rect) {
   return false;
 }
 
 gfx::Vector2d GLSurface::GetDrawOffset() const {
   return gfx::Vector2d();
 }
 
+void GLSurface::WaitForSnapshotRendering() {
+  // By default, just executing the SwapBuffers is normally enough.
+}
+
 GLSurface* GLSurface::GetCurrent() {
   return current_surface_.Pointer()->Get();
 }
 
 GLSurface::~GLSurface() {
   if (GetCurrent() == this)
     SetCurrent(NULL);
 }
 
 void GLSurface::SetCurrent(GLSurface* surface) {
@@ skipping 179 matching lines @@
 }
 
 bool GLSurfaceAdapter::SetDrawRectangle(const gfx::Rect& rect) {
   return surface_->SetDrawRectangle(rect);
 }
 
 gfx::Vector2d GLSurfaceAdapter::GetDrawOffset() const {
   return surface_->GetDrawOffset();
 }
 
+void GLSurfaceAdapter::WaitForSnapshotRendering() {
+  surface_->WaitForSnapshotRendering();
+}
+
 GLSurfaceAdapter::~GLSurfaceAdapter() {}
 
 scoped_refptr<GLSurface> InitializeGLSurfaceWithFormat(
     scoped_refptr<GLSurface> surface, GLSurfaceFormat format) {
   if (!surface->Initialize(format))
     return nullptr;
   return surface;
 }
 
 scoped_refptr<GLSurface> InitializeGLSurface(scoped_refptr<GLSurface> surface) {
   return InitializeGLSurfaceWithFormat(surface, GLSurfaceFormat());
 }
 
 GLSurface::CALayerInUseQuery::CALayerInUseQuery() = default;
 GLSurface::CALayerInUseQuery::CALayerInUseQuery(const CALayerInUseQuery&) =
     default;
 GLSurface::CALayerInUseQuery::~CALayerInUseQuery() = default;
 
 }  // namespace gl